Sheet



B. L. WORTHtN. CU. v. K. woRTHEN, Ex Rlx.

` APPLICATION FILED OCT. lll Q. go f Patented D00. 50,1919. l I 3 SHEETI' 'SHE 3- q i9 y Ja 55 41 i V J7 40 v -J WDM# / Mmm-.Zim

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srarns ramena-r onirica.

ABURII' L. l/VORTHEN, OF CHICAGO, ILLINOIS; VIRGINIA K. WORTHEN EXECUTRIX OF SAID BURT L. WORTHEN, DECEASED.

DRILL. l

` Application led October 11, 1917. Serial No. 195,942.

To all whom it. may concern.; 'i Be it known that I, BUii'i L. VVORTHEN, a

citizen of the-United States, and a resident which the following is a specification.

My invention relates to improvements in .d rills, and particularly to what is vknown and has the following objects'y scribed and claimed, it being understood that lchanges in the precise embodimentof the invention mav be made within thescope of.

as rock drills,

inview: v y

To provide a rock drill containing a-`pis ton-hammer member having unhampered reciprocating action,l thus forming what. I term a free-running hammer, 'suitable means being provided for revolving or turning the dril To provide a rock drillhaving arsleeve cylinder capable of revolving about its lon-l gitudinal axis and connected to, so `as to rotate, the drill, and in which rotating cylin? jder is placed a piston hammer capable 'ofv free reciproeation therein, so that the entire impact of the hammer is brought to bear upon the drill point, the return. motion of thepiston hammer takesplace in an uiiretarded Vmanner and 'is accomplished in a -minimumamount of time, lso that the drill may operate at a high speed.

To provide aii'improved construction of- 4drill `havinga rotating -cylinder in which is placedv a free-running hammer and combining therewith an admission and exhaust valve operated Aby the combined action of'l the hammer and Aair pressure, the arrange- Y ment heilig s'uch that the valve is capable of rapid motion, consistent withthe high speed at which -the piston hammer may reciprocate, so that the drill may operate at a high speed; and further, provid-ing, bv means of an early and `quick cut-off of the admission ports, an economicallv running drill. To provide 4a drill combining certain new and nov-el features for revolving thedrill without interfering with thefreereciproCa-- tion or ruiming of the piston hammer.

To provide` a rock drill' having an ini'- proved form of chuck wherebythe drill point or steel is properly'held in position in the drill and is balanced by air' pressure so thatthe drill may be rotated without undue p.

friction. y y

To provide a drill which will operate effi; cieutly andefiectively .over a Wide range oi' speed and in various types of rock or other material, and a drill capable of withstand` .,ing. the extremely severe `usage to which api `Specification of Letters Patent. Fatnijed Dec. 30, 1919. y

pai'atus of this class are necessarily sub-v4 jected. l

With the foregoing and other objects. in

view,'which'\vill appear as the descriptionproceeds, my invention resides in the com-` bination and arrangement of parts and in.

the details of construction hereinafter deings, wherein:

Figure l is a vieiv in longitudinal vertical sectiQn of my improved rock drill, the pis-Y ton liaminerbeing at its rearmost position and the valves so placed as to causethe rapid forward propagation or movement of the hammer upon its'jvorking stroke;

Fig. 2 is a similar View showing the hammerat tliecompletion .of its working stroke vand at the'extremi forward end of the cylin- Sder, the valves now occupying a position for admitting pressure at the forward end ot the cylinder for the free return stroke ofthe hammer, the rear-'end of the cylinder being opened tothe atmosphere through the eX h a ust ports Fig. 3 is a top plan view of the hammer, parts .being brokenl awayv to disclose the structural Vfeatures thereof; V

VFiga-1l is a fi'agmental view inside elevation of the rear end of the drill, portions of the oilng system being broken away, disclosing the manner in w-liiclioil is fedinto 'l the drill Fig. 5 isV a fragmental llview in vertical section taken onthe `line 5.5 of Figi;

tion of the drilltakenA on Athe line 6 6 of y Fig. l; Fig. 7 being a similar view taken on eoI ` Fig. G is a'view in transverse vertical secl ioo iut

vided with lbalance or pressure, allowing them to freely rotate; l

' `its longitudinal axis, but held'against slid- Fig.' 9 is a view in end elevation, taken on the line 9 9 of Fig. 4, the parts being removed. I

Fig. 10 is a view in vertical section taken on the line 10-10 of Fig. l;

` Fig. 11 is a fragmental view partially in side elevation and partially'in vertical section, sho-wing the means whereby the cylin.-

' der, and therefore the drill, is rotated, and

adjacent parts of the main controllingvalve; and

Fig. 12 is a view in vertical transverse section taken on the line 12-12 of Fig.l 2.

Referring specifically to the sevei'jal views, my improved rock drill comprises an outer and main casing 10', inwhich is mounteda sleeve cylinder 1l, capable of turning about ing or reciprocating, as will hereinafter ap-y pear.

Mounted within the cylinder. l1 and adapted to freely reciprocate therein,l is the piston hammer. 12, from the rear end of which extends a projectionv or plunger 13.

mer so as to receive the water and air supply v tubelj` therethrough, the arrangement being suoli that the hammer is adapted to reciprocate freelyV within the cylinder, so that the drill may operate at a high'speed, and in-` suring that the maximum impactwill belhad vupon theI head of the drill rod or steelat' the end o-f each working stroke.

In order to control the admission and exhaust of pressure to and from the cylinder,

to insure the rapid operation of the drill.

and to provide for the economical use of the the surface of the cylindrical portion adjacent its rear end as at 22, forming ports which are first brought into aliii'einent with air supply ports 23 and .then with exhaust ports or openings 24, thuseontrolling the admissiofi ofpressure to, and the exhausting ofl Y, pressure from, the rear extremity of the cylinder. The valve member 17 is reciprocated bv providing it with an enlarged flange `25 which acts in the manner of a piston and is of such size that when pressure is admitted therebehind through suitable ducts 26 which communicate with the air suppl)Y ports or passages 23` the pressure acting upon the rear surface of the valve is greater than that acting upon the forward surface of the An opening 14 extends axially through the hamvalve within the cylinder, so that the valve will be driven forwardly xfrom the positionshown in Fig. 1 to that illustrated in Fig. 2,

the hammer 12 being simultaneously p ro- K jected forward on its working stroke and v1mpacting with the extremity 27 of thejdrill rod; the pressure behind the hammer,

causing its forward propagation, entering through the-air supply passages 23, por'ts22 and ducts 21, the former communicating with the air supply pipe`28.

AThe valve, as it passes to its forward-position illustrated inFig. 2, cuts o' the admis-v sion of air behind the hammer 12 and pro'- vides for the admission of air to the forward extremityof the cylinder through .the front admission ports 28; theseports being opened as the flange ofthe valve member passes forwardly; air pressure being admitted to the passages -29 ,which extend from the rear head of the cylinder forwardly, as shown in Fig. et, andl terminateat the Vchannel 29 at-the adjacent forward extremity of the cylinder.- The sleeve cylinder is provided with openings 30 which are in constant communication with the channel 29',- and therefore with the air .supply passages 29. The casing 10 and cylinder 11 are provided with the exhaust ports 30 and 31', which communicate with thev exhaust pipe 32 and are so located that as the hammer is projected forwardly on its working stroke, air is relieved from thereinfront during the initial part of the stroke through the forward sets of exhaust" ports 31, the pressure being relieved from ,thereinfront during the remainder of the stroke by the air escaping through the .drill`v rod, aswill hereinafter appear, and through the front: portion' of the drill* to produce a balancingeffect upon those parts. as will also be hereinafter explained. The pressure to the rear of the piston hammer upon its return stroke is relieved by the exhaust' ports 31', and by reason of the fact that the ducts 21'are no-w 11i communication with exhaust ports 24 provided in the valve guide member 18; the exhaust ports 24, as illustratedin Fig; 2, communicating in turn with the exhaust pipe 32. I

The projection or plunger 13 upon th rear extremity of the hammer, isadapted to enter within therecess 33 provided in the forward extremity of the valve, and, compressing the air therein, causes the rearward or return movement of the valve, the same being readily accomplished as the pressure behind the plunger 2.5 is relieved'asthe airpassages 29 are now in communication with the exhaust pipe 32 through the medium of the channel 29', cylinder openings 30 and 31. The -compression of air which takes place when the plunger 13 of the hammer Y entersvthe recess 33, not only provides for the rapid returnmovement of the valve to its initiall position, but acts to check the rearward movement of thel hammer, forms nan elastic cushion therefor, and materially aids in-the rapid forward propagation of the hammer, which takes place immediately upon the admission -of pressure from the` rear portionofthe cylindertcaused by the return-'of the valve.`

To reiterate, with the valve and-hammer in the positions as'l shown in Fig. V1`, pres;v `.10 sure enters4 to. the rear of the hammerl -through passage's'23, ports 22, ducts 21, and

forcibly moves thehammer forward. Pres- 1 sure in front of the. hammer is relieved.

through the exhaust ports 31 and through the `opening containedin the'drill lpoint shaft.- 'As the hammer is propagated forward, pressure' enters to the rear 'of the valve flange 25, through the duct 26,' causing the valve to shift forward, so thatl at the time the 20 hammer reaches the forward extremityof,l

its working stroke the valve .1T-has shifted, admitting pressure tothe forward extremity ofthe cylinder through the *admission ports 28, air pas'sages`29, `and openings 29 and 30, causing the return of the .hammer,pres' sure being allowed to escape or 'exhaust fromtherear of the cylinder through the ports`31 and through the ducts 21 and exhaust passages 24. As thehammer nears 30 the extremity ofl its stroke, the plunger 13,

entering the receptacle or cup 33, 1carries' the valve rearwardly andthus completes a cycle of operation.

Inv drills of the present character, it

-35 necessary to revolveV the drill steel, and tothis end it has heretofore been the practice (to insoine way;conn'ect the hammer with the drill steel.d 'Such arrangement, however,

y materially interferes with the rapid work- 40 ing of the hammer, and in order to overcome such objections and provide' a drill -which may operate at 'a much higher rate of speed than heretofore thought practical,

I provide a separate cylinder 34sextendingr at right anglesto the main cylinder and in- "'which is located a piston 35. The reciprovcation of this piston corresponds with the reciprocation ofthe hammer,'and it is accomplished' by providing the cylinder in. which it operateswithends of diferent diametersand' maintaining vvwithin the smaller 'end 36 a constant air pressure through the air supply passage 37 which communicates withLthe air supply\pipe 28 o-f the drill. The constant -air pressure within theend 36 ofthe cylinder tends to maintain the auxiliary piston at-"the-far and larger ex- Atremit'y 33 `of the-cylinder. The larger extremity 38 of4 the cylinder communicates with the rear extremity of the main c vli-nder 11 by the passage 39, so that while the foi-,v ward and-smaller extremity of the cylinder 34 is subjected to constant air pressure the remote and larger extremity of, the cylinder' is alternately exposed or supplied with such airpressure, and by reason of the'larger di ameter of this end of the piston, the piston is alternately driven forward and Areturned to'correspond with. the reciprocations of the 'piston hammer 12.

is transmitted to a ratchet ring 40 by a projection or Alug- Ll1, thc ratchet ring in turn oscillating to and fro upon the valve guide riiigl8.' The ratchet ring is pro- -vidediwithratchet teeth ft2 which Vengage .Uw-ith corresponding teeth 43 formed or secured tothe end ofthe cylindrical sleeve 11.I These teeth may beprovided directly upon the end yof the rotating sleeve or cylinder-11 adjacent which the oscillating ratchet ring 40 operates or, as bestyshown in Figs.

-1 and 2,'the said teethmay be formed upon 4a ring separate fiom the cylinder and hav# `ing an inter-'locking engagement ltherewith to drive the same; the upper `portions of these figures showing a lug on the cylinder extending .through `a 4recess formed` in the inner edge lof the toothw'carrying ring, while the lower portions of said figures show a lug extending inward from the inner edge,

of said ring and. lying between 'two lugs carried by the rotating cylinder. A' spring or resilient member 44 extends to the rear of the oscillating ratchet ring 40 and holds the teeth thereof in mesh with `the ratchet teeth of the cylinder 1l. hammer 11 reciprocates, a synchronous motion is assumed by the piston 35, which latter oscillates the ratchet ring, which in turn picks up the teeth of the c vlinder 11 and ro- .tates the latter 'through a certain arc, the rotation of the cylinder. heilig accomplished during Athe stroke of the auxiliary piston 3a when jacted upon by 'the constant air presrecesses '19' foi-mcd in the end of the c vlin-A der 11. Thus as the cylinder ll is rotated, a corresponding movement is imparted to the drill. chuck 4T and thence to the drill 27 .70 The reciprocating Amotion ofthe piston 35 Thus as the piston The chuck l? is held in place within the.

forward extremity of the drill and at the sametinie mounted for free rotationby providingthe front head 50 of the drill with an enlarged recess 51 adjacent its rear extremityand clampingwithin said recess a split sleeve or ring 52; The split ring 52 abuts aainst a shoulder at the rear ex- .tremity of the casing 10, and a shoulder 54 of the front head, and is accordingly held V- rigidly in place. The-split ring also conl tacts with the shoulders'55 and 56 provided upon the chuck 47, so that the chuck is held against lengthwise movement but may freely rotate. In order to maintain the drill point in place within'the chuck, a fastening ring 57 is provided, having openings 58 adapted to receive the lugs 45 of the drill vpoint therethrough, and the ring is further provided with a tooth 59V which engages with a corresponding opening 60 in the extremity of the chuck, the tooth and opening being so located as to hold the lug openings 458 of the fastening ring and the lug open- .ings 46 of the chuck out of alinement, so that after the ring has been passed lover the lugs'and the lugs inserted within the re cesses 46of the chuck and the ring rotated so as to bring the tooth '59 into engagement with the recess 60, said drill is-locked in.

place and the ring is held so the front head 50 of the drill.

',The split ring 52` is providedwith the' grease pockets 52 in which a lubricant may positioned by bev injected through the passage 52 illus# trated inv Fig. 3, the same heilig provided j with an external cap. In order that the f communicating with th'e air pressure within vchuck, and cylinder may freely rotate, the

front head of the drill is provided with an air passage 'A communicating with the air inlet supply pori; 29. The passage A extends to the forward end of the drill head and communicates with a recess 57 formed in the fastening ring 57. The remote eX- tremity of thesplit ring and the adjacent parts of the drill chuck arefprovided with the channels B forming cushionpockets the. forward part of the cylinder 11, so that the chuck, fastening ring and split ring are balanced with regard 'to pressure and the cylinder and vchuck may accordingly rotate without undue friction.

The casing 10,v rear head l'16, and front Ihead 50,y are provided with outstanding perforated ears 61, through which extend hold.

A ing rods 61',` clamping the heads to the casj ing. The casing and rear head are further y provided with outstanding .perforated projections C,'allowin'g the 'drill to b'e readily mounted upon a drill stand. The water andl air supply tube 15 which extends'axiallythrough an opening in the hammer, terminates at its forward extremity in the ex-l tremity of the drill, as illustrated in Fig. 1;

- and at ,its rear extremity is provided with. a

packing ring 62 through which small ducts' or openings 63 pass, providing -for the ad'- mission of water under pressuretothe' tube v15. A water and air controlling valve for the drill point is provided in the member.

, 64,- the same being inthe form of a tube, the

water supply flowing from the central open ing 65 d own through the water duct 66 and thence ,through the openingv63 into the tube supply 28) with the air duct 71, the latter extending around the -packing gland 68, as

at 72, and communicating with the rear opening of the tube 15 through the duct 73. Thus when the valve 64 is in `one position, water is supplied .to the drill point; when in a, second position, air under pressure is supplied to the drill point for cleaning the drilled hole; while a third position of the valve shuts olf both the air and water sup-v ply. The extremit of the'water supply tube' 15 is somewhat reduced in diameter and extends within the opening 74 in the drill point; a loose lit being provided so that air pressure may also enter from the cylinder 11 into the opening 74 of the drill and thence to the drill vpoint pro-per.

The high speed at which they drill is adapted to operate renders necessary a thorough lubrication of the drill at all times, and to this end I have provided a lubricant receptacle or chamber 8O formed in the rear head 16 of the drill. Oil .or other lubricant" is introduced within the chamber 80I through the 'opening S81, the same' being normally' lug 82.. Located within the Y lubricant cham er 8O is the sleeve 83which closed by the contains packing 84l therein, and communicating'with the lubricant chamber 80 andv with the sleeve 83, are the cross tubes 85,

their function being toallow oil to escapev or pass from the lubricant chamber 80 into the sleeve 83, the cross tubes having small openings 86 and 87 for this' purpose. The

extremityof the oil-distributing sleeve 83 is provided with outlet openings 88 communicatingA with the air supply pipe 28 by the andthe chamber 80'is in turn subjected to the fluctuating pressurecf the smaller end of the auxiliary cylinder 34, a predetermined quantity of o-il or other lubricant will Vbe forced from the lubricantchamber 80 into the oildistributing sleeve 83 as the pressure within.. the smaller end 36 of the auxiliary cylinder is the said auxiliary cylinder. The pressure which is .momentarily backed -up' in the smaller end of thel auxiliary-cylinder, causes. the oil or lubricant to be forced into the sleeve 83 and thence into the air supply l increased. when the auxiliary pis.y tenisv driven upon.1ts return stroke as air pressure 1s admitted into the larger end of pipe 28,l the packing or waste within the sleeve 83 limiting the amount of oilwhich is thus supplied upon each reciprocation 'of the auxiliary piston. Inasmuch as the auxiliary pistonv which is used toreciproifate the cate within said cylinder and strike said drill point, an inlet andexhaust valve adapted' tol control the `supply of air under.

pressure to, and the exhaust thereof from, the interior of said cylinder, and vmeans whereby the movements of vsaid valve are .\'jointly controlled by the supply pressure of the drill aiidby the impact of the piston hammer at the completion of itsreturn orv non-working stroke.

, 2. A drill consisting of a casing, a. drill chuck atthe forward extremity thereof and mounted for rotation therein, a cylinder s0 mounted'witliin said casing adapted to rotate about its-longitudinal axis and engaging, and adapted to rotate, said chuck, a piston hammer mounted/'foi'. unhamperedorA free reciprocation withinsaid cylinder, and

Within a portion of said cylinder adapted to intermittently rotate, the said cylinder for the rotation ofthe said chuck andthe drill point which it is adapted to support. 3. A drill consisting of a casing, a cylinder therein mounted for 'rotation about its longitudinalaxis, a chuck contained with! in 'the lforward extremity of said casing, mounted for rotation therein, and means whereby the pressure uponthe forward extremity of'said chuck is balanced-so as toV reduce the frictional resistance Vto rotation thereof, a piston hammer mounted for freereciprocation within said cylinder, means for controlling the supplying and exhaust'- n ing of pressure insaid cylinder, for 'thereciprocation of said hammer.

A4l. A drill consisting of a casing, a cylinder therein mounted forl rotation about' auxiliary means controlled by-the" pressure means, mechanically independent and functionally dependent upon the reciprocation of said piston hammer, adapted to rotatethe .said cylinder; 'Y

5.. A drill comprising a casing, a cylinder -76 mounted for rotation therein, a piston ham.- nier adapted to reciprocate within said cylinder, an' auxiliary cylinder carried by said casing .provided with ends of different l diameters, an auxiliary piston having ends of' vdifferent diameters fitting within said auxiliary cylinder, means whereby the* smaller end of said-cylinderl to the rear of said piston is exposed to constant air pres sure, and the largerrend of said'auxiliary 80 Apiston intermittently exposed i the same constant air pressure forthe intermittenty reciprocation of said auxiliary piston, and means ,whereby the reciprocation of said auxiliary piston rotates said Hist-mentioned cylinder. i

6. A drill comprisinga cylinder, a piston hammer mounted for reciprocation therein and adapted to impact with a drill point ,an auxiliary cylinder haviig ends of unequal bore cairiedby said iirst-nientioned cylinder,

`a piston having ends of unequal. diameter fitting within said auxiliary cylinder, the smaller extremity of said auxiliary cylinder communicating with the air supply of said drill, therla'rger extremity of said auxiliary -cylinder communicating with the one extremity of said main cylinder, whereby the auxiliary piston reci-procates synchronously with the reciprocation of the said pistonhammer, and means whereby the reciprocavtion of said auxiliary piston is adapted to rotate lthe drill point of the drill. l

' 7. A drill comprising a cylinder,- a pis- .ton hammer mounted for reciprocationio therein, an auxiliary 'cylinder carried by said main cylinder, with one extremity thereof communicating .with one extremity of said main cylinder, an auxiliary piston mounted within said auxiliary cylinder, means for-iiiaiiitaining said'auxiliary piston at one extremity of said auxiliary cylinder, opposite to the extremity said auxiliary piston is forced by the pressure'received from the main cylinder, means Wliereby the drill point is held to said drill and receives there-` onthe 4impact of said piston hammer, and means wherebythe reciprocation of the auxiliary piston rotates said drill point.l

8. A drill comprising a casing, a sleeve-12o mounted for rotation' therein, a hammer mounted for reciprocation within said sleeve, a drill chuck carried at the forward extremity of said casing and provided with inter-locking means engaging said cylinder and 12 5 adapted to be rotated thereby, a ring engaging said chuck holding the same against endwi's'e movement and :mounting it for rota. tion, af front headl engaging said-casing and y clamping said ring in place, said chuck pro .180

. be rotated by said cylinder,

, vof said piston hammer to retain the lugs of the vbe rotated by said cylinder,

, located at' the rear ble cylinder and in vided with an axial opening and communicating recesses adapted to receive theoffset lugs of a drill point therein, and a locking ring adapted to retain the lugs of the drill point within said recesses.

9. A drill comprising a casing, a sleeve mounted for. rotation therein, a hammer mounted.forreciprocation within said sleeve, a drill chuckcarried at the forward extremity of said-casing and provided with interlocking vmeans engaging said cylinder and adapted to be rotated thereby, a ring engaging said chuck holding the same against endwise movement and mounting it for rotation, a front head engaging said casing and clamping said ring inplace, said chuck provided with an axialopening and communicating recesses adapted to Vreceive the offset lugs of a drill point therein, a lockingring adapted drill point within said recesses, and means mechanically independent of said hammer adapted to rotate said cylinder. 10. A drill consisting of a-casing, a cylinder mounted for rotation therein, a drill point carried b y said casing and adapted to an auxiliary cylinder carried by said casing,,an-auxiliary piston mounted therein, a piston hammer mounted within said main cylinder, means whereby the pressure in said auxiliary cylinder iscontrolled by the pressure'within the main cylinder for ,synchronous reciprocation and auxiliary piston, said rotatable cylinder provided with ratchet teeth thereon, a ratchet ring engaging the ratchet teeth of the cylinder and connected vto 1said auxiliary piston, for the intermittent rotation ot said cylinder with the reciprocation ,of said auxiliary piston, and means for controlling the pressure in the front and rear extremities ot said rotatable cylinder. 11. A drill consisting of a casing, a cylinder mounted for rotation therein, a drill point carried bysaid casing and adapted to an auxiliary cylinder carried by said casing, an auxiliary piston mounted therein, a piston hammer mounted Within said'main cylinder, means whereby the pressure in said auxiliary cylinder is controlled by the pressure within the main cylinder for synchronous reciprocation of said piston hammer and auxiliary piston, said rotatable cylinder providedwith ratchet teeth thereon, a ratchet ring engaging the ratchet teeth of the cylinder and connected to said auxiliary piston, for thelintermittent rotation of said cylinder with the reciprocation of said auxiliary piston, a piston valve the path oftravel of the a projection carried by said piston hammer, Y

adapted to enter within said piston hammer piston valve,

`auxiliary cylinder chronously with extremity of.v said rotataf a 'recess formed in said piston valve for checking the motion ofsaid' piston hammer and causing the return movement `of said and means whereby an unbalanced pressure is impressed upon said piston valve when the 'latter is in its rearmost position, said piston valve controlling 'the-pressure within the extremities of said cylinder.

l2. A. drill comprising a cylinder, a piston hammer mounted -for reciprocation therein and adapted to impact with a drill point, an auxiliary cylinder having ends of unequal bore carried by said first-mentioned cylinder,

a piston having ends of unequal diameter ftting within said auxiliary cylinder, the smaller extremity of said auxiliary cylinder communicating with the air supply, ot said drill, the larger extremity of said auxiliary cylinder communicating` with the one extremity of said'main cylinder, whereby vthe auxihary plston reciprocates synchronously `with the reciprocation of the said piston hammer, means `whereby the reciprocation of. said auxiliary piston is adapted to rotate the drill point of the drill, a lubricating chamber carried by said drill,'said lubricating chamber provided withia pressure inlet port communicating with the smaller extremity ot said auxiliary cylinder and proiided with a lubricant. outlet port communieating' with the air supply of the drill.

13. A drillcomprising a cylinder, a piston hammer-lm ounted for reciprocation,therein and adapted to impact with a drill point, an auxiliary cylinder having ends of unequal bore carried by said first-mentioned cylinder, a iston having ends of unequal diameter tting within said auxiliary cylinder, the smaller extremity of said auxiliary cylinder communicating with the air supply of said drill, the larger extremity of said by the auxiliary piston reciprocates synthe reciprocation of the said piston hammer, mean-s whereby the reciprocation ot' said auxiliary piston is adapted to rotate the drill point of the drill, a lubricating chamber carried by said drill, said lubricating chamberA provided with a pressure inlet port comnmnicating with the smaller eX- tremity of said vided with a lubricant outlet port communieating with the air supply ot the drill, and a sleeve having radially extend-ing tubes communicating`l with the said outlet lubricant port.

Signed at Chicago, in the county of Cook A. D. i917. i

. BURT L. VVORTHEN.- lVitnesses:

JOHN BIDERBERG, ALFRED MACK,

conmiunicating with the one extremity of said -main cylinder, whereauxiliary cylinder and pro- 

